Navy blue short sleeve, knit top with shallow scoop neck

Navy blue, short sleeve, knit top with shallow scoop neck. Unfortunately, I don’t know anything else about this top. I am assuming it is most likely a medium. I can confirm that it is a very nice knit, which would most definitely be cool for the summer. Armpit to armpit measures 18.5” Shoulder seam to bottom measures 21” This top has never been worn (NWOT)